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JWT Decoder Guide

Learn how to decode, inspect, and encode JWTs safely

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🔐 JWT Decoder & Encoder: Complete Guide

Our JWT Decoder/Encoder helps you safely inspect, validate, and craft JSON Web Tokens. Decode an incoming token to review its header, payload, and signature components, or encode a fresh payload to generate a new token for testing and QA.

✨ What the tool does

  • Decode JWTs to view header, payload, and signature segments in plain JSON.
  • Validate token structure and quickly spot expired or malformed claims.
  • Encode custom payloads to test auth flows, role flags, or sandbox APIs.
  • Copy decoded sections for documentation, debugging, or support tickets.

🚀 How to use it

  1. Paste a JWT token into the decoder and click Decode to view header and payload JSON.
  2. Inspect claims (iss, sub, aud, exp, roles) and timestamps to verify authenticity and lifetime.
  3. Switch to encode mode, enter a payload, and generate a signed token for testing.
  4. Copy header/payload/signature or the full token to share with teammates or drop into Postman.

Note: This tool is for local inspection and testing. Always keep production secrets (keys, private claims) safe.

🔧 Encoder vs Decoder

Decoder

Takes an existing JWT, splits it into header, payload, and signature, and renders JSON for human-readable review.

Encoder

Accepts a JSON payload and produces a JWT string for testing claims, roles, or expiry behavior in your apps.

📌 Best practices

  • Use decoded claims to confirm audience, issuer, and expiry before trusting a token.
  • Never paste private keys; this tool is for inspection, not signing with production secrets.
  • For QA, encode tokens with short expiries and mock roles to test access control.

Try the JWT Decoder/Encoder

Paste a token, inspect the claims, or generate a test token in seconds.

Open JWT Decoder →

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